The term "motor" is used herein generally, in the sense of a device to impart motion or apply force in response to an energy input thereto. In one embodiment disclosed below, motors of pressure fluid actuated rotary or linearly moving type are employed.
Automatic samples are known and have been employed in connection with automated high pressure liquid chromatography. However, we have found that it is possible to effect certain improvements in apparatus of this general type.
Accordingly, the objects of this invention include provision of:
An apparatus for sampling by a probe of sequentially presented containers on a movable rack in which movement of the rack as well as a probe is effected by pressure fluid operated motors in a housing supporting the probe and rack, in which actuation of the pressure fluid motors and other devices controlled to operate in sequence therewith, as for operating a liquid chromatography system, avoid the use of electromechanical relays, motors, limit switches, or other open electromechanical devices within the housing, and wherein generation of sparks and corresponding danger in use of readily ignitable volatile liquids as rinse or sample liquids is reduced.
Apparatus, as aforesaid, in which rack rotation and at least vertical probe movement are independently controllable through independent pressure fluid operated motors for maximum flexibility of moving one with respect to the other either manually for set-up purposes or to permit sampling of containers out of their sequence of arrangement on the rack.
Apparatus, as aforesaid, in which panel means within the housing are provided for onboard, internal location of a microprocessor circuit programmable to control sequencing of the pressure fluid motors moving the probe and sample rack, as well as a sample injection valve for a chromatography column, which onboard microprocessor circuit is in addition to and distinct from an external (host) computer of the type normally used for processing data from sample analyzing means such as a chromatographic detector.
Other objects and purposes and purposes will be apparent to persons familiar with apparatus of this general type upon reading the accompanying specification and inspecting the accompanying drawings.
The objects and purposes of this invention are met by providing apparatus for establishing fluid communication between a probe unit and a plurality of containers presented in a controlled sequence to a sampling position in which a rack unit is adapted to hold the containers for movement into and out of the sampling position and a hollow probe unit is supported by a probe holding unit and is movable thereby into and out of the sampling position. A drive connects to the rack unit and probe unit for effecting and controlling their movements. The drive includes a first pressure fluid operated motor actuable for moving the probe unit into and out of the sampling position for communication with containers thereat and a second pressure fluid operated motor actuable for causing the rack unit to move a desired one of the containers to the sampling position, the first and second pressure fluid operated motors being actuable independently of each other from a common pressure fluid source.